net/bridge/br_vlan.c

   1 #include <linux/kernel.h>
   2 #include <linux/netdevice.h>
   3 #include <linux/rtnetlink.h>
   4 #include <linux/slab.h>
   5
   6 #include "br_private.h"
   7
   8 static void __vlan_add_pvid(struct net_port_vlans *v, u16 vid)
   9 {
  10         if (v->pvid == vid)
  11                 return;
  12
  13         smp_wmb();
  14         v->pvid = vid;
  15 }
  16
  17 static void __vlan_delete_pvid(struct net_port_vlans *v, u16 vid)
  18 {
  19         if (v->pvid != vid)
  20                 return;
  21
  22         smp_wmb();
  23         v->pvid = 0;
  24 }
  25
  26 static void __vlan_add_flags(struct net_port_vlans *v, u16 vid, u16 flags)
  27 {
  28         if (flags & BRIDGE_VLAN_INFO_PVID)
  29                 __vlan_add_pvid(v, vid);
  30
  31         if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
  32                 set_bit(vid, v->untagged_bitmap);
  33 }
  34
  35 static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
  36 {
  37         struct net_bridge_port *p = NULL;
  38         struct net_bridge *br;
  39         struct net_device *dev;
  40         int err;
  41
  42         if (test_bit(vid, v->vlan_bitmap)) {
  43                 __vlan_add_flags(v, vid, flags);
  44                 return 0;
  45         }
  46
  47         if (v->port_idx) {
  48                 p = v->parent.port;
  49                 br = p->br;
  50                 dev = p->dev;
  51         } else {
  52                 br = v->parent.br;
  53                 dev = br->dev;
  54         }
  55
  56         if (p) {
  57                 /* Add VLAN to the device filter if it is supported.
  58                  * Stricly speaking, this is not necessary now, since
  59                  * devices are made promiscuous by the bridge, but if
  60                  * that ever changes this code will allow tagged
  61                  * traffic to enter the bridge.
  62                  */
  63                 err = vlan_vid_add(dev, br->vlan_proto, vid);
  64                 if (err)
  65                         return err;
  66         }
  67
  68         err = br_fdb_insert(br, p, dev->dev_addr, vid);
  69         if (err) {
  70                 br_err(br, "failed insert local address into bridge "
  71                        "forwarding table\n");
  72                 goto out_filt;
  73         }
  74
  75         set_bit(vid, v->vlan_bitmap);
  76         v->num_vlans++;
  77         __vlan_add_flags(v, vid, flags);
  78
  79         return 0;
  80
  81 out_filt:
  82         if (p)
  83                 vlan_vid_del(dev, br->vlan_proto, vid);
  84         return err;
  85 }
  86
  87 static int __vlan_del(struct net_port_vlans *v, u16 vid)
  88 {
  89         if (!test_bit(vid, v->vlan_bitmap))
  90                 return -EINVAL;
  91
  92         __vlan_delete_pvid(v, vid);
  93         clear_bit(vid, v->untagged_bitmap);
  94
  95         if (v->port_idx) {
  96                 struct net_bridge_port *p = v->parent.port;
  97                 vlan_vid_del(p->dev, p->br->vlan_proto, vid);
  98         }
  99
 100         clear_bit(vid, v->vlan_bitmap);
 101         v->num_vlans--;
 102         if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
 103                 if (v->port_idx)
 104                         RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
 105                 else
 106                         RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
 107                 kfree_rcu(v, rcu);
 108         }
 109         return 0;
 110 }
 111
 112 static void __vlan_flush(struct net_port_vlans *v)
 113 {
 114         smp_wmb();
 115         v->pvid = 0;
 116         bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
 117         if (v->port_idx)
 118                 RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
 119         else
 120                 RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
 121         kfree_rcu(v, rcu);
 122 }
 123
 124 struct sk_buff *br_handle_vlan(struct net_bridge *br,
 125                                const struct net_port_vlans *pv,
 126                                struct sk_buff *skb)
 127 {
 128         u16 vid;
 129
 130         if (!br->vlan_enabled)
 131                 goto out;
 132
 133         /* Vlan filter table must be configured at this point.  The
 134          * only exception is the bridge is set in promisc mode and the
 135          * packet is destined for the bridge device.  In this case
 136          * pass the packet as is.
 137          */
 138         if (!pv) {
 139                 if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
 140                         goto out;
 141                 } else {
 142                         kfree_skb(skb);
 143                         return NULL;
 144                 }
 145         }
 146
 147         /* At this point, we know that the frame was filtered and contains
 148          * a valid vlan id.  If the vlan id is set in the untagged bitmap,
 149          * send untagged; otherwise, send tagged.
 150          */
 151         br_vlan_get_tag(skb, &vid);
 152         if (test_bit(vid, pv->untagged_bitmap))
 153                 skb->vlan_tci = 0;
 154
 155 out:
 156         return skb;
 157 }
 158
 159 /* Called under RCU */
 160 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
 161                         struct sk_buff *skb, u16 *vid)
 162 {
 163         bool tagged;
 164         __be16 proto;
 165
 166         /* If VLAN filtering is disabled on the bridge, all packets are
 167          * permitted.
 168          */
 169         if (!br->vlan_enabled)
 170                 return true;
 171
 172         /* If there are no vlan in the permitted list, all packets are
 173          * rejected.
 174          */
 175         if (!v)
 176                 goto drop;
 177
 178         proto = br->vlan_proto;
 179
 180         /* If vlan tx offload is disabled on bridge device and frame was
 181          * sent from vlan device on the bridge device, it does not have
 182          * HW accelerated vlan tag.
 183          */
 184         if (unlikely(!vlan_tx_tag_present(skb) &&
 185                      skb->protocol == proto)) {
 186                 skb = vlan_untag(skb);
 187                 if (unlikely(!skb))
 188                         return false;
 189         }
 190
 191         if (!br_vlan_get_tag(skb, vid)) {
 192                 /* Tagged frame */
 193                 if (skb->vlan_proto != proto) {
 194                         /* Protocol-mismatch, empty out vlan_tci for new tag */
 195                         skb_push(skb, ETH_HLEN);
 196                         skb = __vlan_put_tag(skb, skb->vlan_proto,
 197                                              vlan_tx_tag_get(skb));
 198                         if (unlikely(!skb))
 199                                 return false;
 200
 201                         skb_pull(skb, ETH_HLEN);
 202                         skb_reset_mac_len(skb);
 203                         *vid = 0;
 204                         tagged = false;
 205                 } else {
 206                         tagged = true;
 207                 }
 208         } else {
 209                 /* Untagged frame */
 210                 tagged = false;
 211         }
 212
 213         if (!*vid) {
 214                 u16 pvid = br_get_pvid(v);
 215
 216                 /* Frame had a tag with VID 0 or did not have a tag.
 217                  * See if pvid is set on this port.  That tells us which
 218                  * vlan untagged or priority-tagged traffic belongs to.
 219                  */
 220                 if (pvid == VLAN_N_VID)
 221                         goto drop;
 222
 223                 /* PVID is set on this port.  Any untagged or priority-tagged
 224                  * ingress frame is considered to belong to this vlan.
 225                  */
 226                 *vid = pvid;
 227                 if (likely(!tagged))
 228                         /* Untagged Frame. */
 229                         __vlan_hwaccel_put_tag(skb, proto, pvid);
 230                 else
 231                         /* Priority-tagged Frame.
 232                          * At this point, We know that skb->vlan_tci had
 233                          * VLAN_TAG_PRESENT bit and its VID field was 0x000.
 234                          * We update only VID field and preserve PCP field.
 235                          */
 236                         skb->vlan_tci |= pvid;
 237
 238                 return true;
 239         }
 240
 241         /* Frame had a valid vlan tag.  See if vlan is allowed */
 242         if (test_bit(*vid, v->vlan_bitmap))
 243                 return true;
 244 drop:
 245         kfree_skb(skb);
 246         return false;
 247 }
 248
 249 /* Called under RCU. */
 250 bool br_allowed_egress(struct net_bridge *br,
 251                        const struct net_port_vlans *v,
 252                        const struct sk_buff *skb)
 253 {
 254         u16 vid;
 255
 256         if (!br->vlan_enabled)
 257                 return true;
 258
 259         if (!v)
 260                 return false;
 261
 262         br_vlan_get_tag(skb, &vid);
 263         if (test_bit(vid, v->vlan_bitmap))
 264                 return true;
 265
 266         return false;
 267 }
 268
 269 /* Called under RCU */
 270 bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
 271 {
 272         struct net_bridge *br = p->br;
 273         struct net_port_vlans *v;
 274
 275         if (!br->vlan_enabled)
 276                 return true;
 277
 278         v = rcu_dereference(p->vlan_info);
 279         if (!v)
 280                 return false;
 281
 282         if (!br_vlan_get_tag(skb, vid) && skb->vlan_proto != br->vlan_proto)
 283                 *vid = 0;
 284
 285         if (!*vid) {
 286                 *vid = br_get_pvid(v);
 287                 if (*vid == VLAN_N_VID)
 288                         return false;
 289
 290                 return true;
 291         }
 292
 293         if (test_bit(*vid, v->vlan_bitmap))
 294                 return true;
 295
 296         return false;
 297 }
 298
 299 /* Must be protected by RTNL.
 300  * Must be called with vid in range from 1 to 4094 inclusive.
 301  */
 302 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 303 {
 304         struct net_port_vlans *pv = NULL;
 305         int err;
 306
 307         ASSERT_RTNL();
 308
 309         pv = rtnl_dereference(br->vlan_info);
 310         if (pv)
 311                 return __vlan_add(pv, vid, flags);
 312
 313         /* Create port vlan infomration
 314          */
 315         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 316         if (!pv)
 317                 return -ENOMEM;
 318
 319         pv->parent.br = br;
 320         err = __vlan_add(pv, vid, flags);
 321         if (err)
 322                 goto out;
 323
 324         rcu_assign_pointer(br->vlan_info, pv);
 325         return 0;
 326 out:
 327         kfree(pv);
 328         return err;
 329 }
 330
 331 /* Must be protected by RTNL.
 332  * Must be called with vid in range from 1 to 4094 inclusive.
 333  */
 334 int br_vlan_delete(struct net_bridge *br, u16 vid)
 335 {
 336         struct net_port_vlans *pv;
 337
 338         ASSERT_RTNL();
 339
 340         pv = rtnl_dereference(br->vlan_info);
 341         if (!pv)
 342                 return -EINVAL;
 343
 344         br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
 345
 346         __vlan_del(pv, vid);
 347         return 0;
 348 }
 349
 350 void br_vlan_flush(struct net_bridge *br)
 351 {
 352         struct net_port_vlans *pv;
 353
 354         ASSERT_RTNL();
 355         pv = rtnl_dereference(br->vlan_info);
 356         if (!pv)
 357                 return;
 358
 359         __vlan_flush(pv);
 360 }
 361
 362 bool br_vlan_find(struct net_bridge *br, u16 vid)
 363 {
 364         struct net_port_vlans *pv;
 365         bool found = false;
 366
 367         rcu_read_lock();
 368         pv = rcu_dereference(br->vlan_info);
 369
 370         if (!pv)
 371                 goto out;
 372
 373         if (test_bit(vid, pv->vlan_bitmap))
 374                 found = true;
 375
 376 out:
 377         rcu_read_unlock();
 378         return found;
 379 }
 380
 381 /* Must be protected by RTNL. */
 382 static void recalculate_group_addr(struct net_bridge *br)
 383 {
 384         if (br->group_addr_set)
 385                 return;
 386
 387         spin_lock_bh(&br->lock);
 388         if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q)) {
 389                 /* Bridge Group Address */
 390                 br->group_addr[5] = 0x00;
 391         } else { /* vlan_enabled && ETH_P_8021AD */
 392                 /* Provider Bridge Group Address */
 393                 br->group_addr[5] = 0x08;
 394         }
 395         spin_unlock_bh(&br->lock);
 396 }
 397
 398 /* Must be protected by RTNL. */
 399 void br_recalculate_fwd_mask(struct net_bridge *br)
 400 {
 401         if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q))
 402                 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 403         else /* vlan_enabled && ETH_P_8021AD */
 404                 br->group_fwd_mask_required = BR_GROUPFWD_8021AD &
 405                                               ~(1u << br->group_addr[5]);
 406 }
 407
 408 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
 409 {
 410         if (!rtnl_trylock())
 411                 return restart_syscall();
 412
 413         if (br->vlan_enabled == val)
 414                 goto unlock;
 415
 416         br->vlan_enabled = val;
 417         br_manage_promisc(br);
 418         recalculate_group_addr(br);
 419         br_recalculate_fwd_mask(br);
 420
 421 unlock:
 422         rtnl_unlock();
 423         return 0;
 424 }
 425
 426 int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
 427 {
 428         int err = 0;
 429         struct net_bridge_port *p;
 430         struct net_port_vlans *pv;
 431         __be16 proto, oldproto;
 432         u16 vid, errvid;
 433
 434         if (val != ETH_P_8021Q && val != ETH_P_8021AD)
 435                 return -EPROTONOSUPPORT;
 436
 437         if (!rtnl_trylock())
 438                 return restart_syscall();
 439
 440         proto = htons(val);
 441         if (br->vlan_proto == proto)
 442                 goto unlock;
 443
 444         /* Add VLANs for the new proto to the device filter. */
 445         list_for_each_entry(p, &br->port_list, list) {
 446                 pv = rtnl_dereference(p->vlan_info);
 447                 if (!pv)
 448                         continue;
 449
 450                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 451                         err = vlan_vid_add(p->dev, proto, vid);
 452                         if (err)
 453                                 goto err_filt;
 454                 }
 455         }
 456
 457         oldproto = br->vlan_proto;
 458         br->vlan_proto = proto;
 459
 460         recalculate_group_addr(br);
 461         br_recalculate_fwd_mask(br);
 462
 463         /* Delete VLANs for the old proto from the device filter. */
 464         list_for_each_entry(p, &br->port_list, list) {
 465                 pv = rtnl_dereference(p->vlan_info);
 466                 if (!pv)
 467                         continue;
 468
 469                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 470                         vlan_vid_del(p->dev, oldproto, vid);
 471         }
 472
 473 unlock:
 474         rtnl_unlock();
 475         return err;
 476
 477 err_filt:
 478         errvid = vid;
 479         for_each_set_bit(vid, pv->vlan_bitmap, errvid)
 480                 vlan_vid_del(p->dev, proto, vid);
 481
 482         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 483                 pv = rtnl_dereference(p->vlan_info);
 484                 if (!pv)
 485                         continue;
 486
 487                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 488                         vlan_vid_del(p->dev, proto, vid);
 489         }
 490
 491         goto unlock;
 492 }
 493
 494 void br_vlan_init(struct net_bridge *br)
 495 {
 496         br->vlan_proto = htons(ETH_P_8021Q);
 497 }
 498
 499 /* Must be protected by RTNL.
 500  * Must be called with vid in range from 1 to 4094 inclusive.
 501  */
 502 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 503 {
 504         struct net_port_vlans *pv = NULL;
 505         int err;
 506
 507         ASSERT_RTNL();
 508
 509         pv = rtnl_dereference(port->vlan_info);
 510         if (pv)
 511                 return __vlan_add(pv, vid, flags);
 512
 513         /* Create port vlan infomration
 514          */
 515         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 516         if (!pv) {
 517                 err = -ENOMEM;
 518                 goto clean_up;
 519         }
 520
 521         pv->port_idx = port->port_no;
 522         pv->parent.port = port;
 523         err = __vlan_add(pv, vid, flags);
 524         if (err)
 525                 goto clean_up;
 526
 527         rcu_assign_pointer(port->vlan_info, pv);
 528         return 0;
 529
 530 clean_up:
 531         kfree(pv);
 532         return err;
 533 }
 534
 535 /* Must be protected by RTNL.
 536  * Must be called with vid in range from 1 to 4094 inclusive.
 537  */
 538 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 539 {
 540         struct net_port_vlans *pv;
 541
 542         ASSERT_RTNL();
 543
 544         pv = rtnl_dereference(port->vlan_info);
 545         if (!pv)
 546                 return -EINVAL;
 547
 548         br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
 549
 550         return __vlan_del(pv, vid);
 551 }
 552
 553 void nbp_vlan_flush(struct net_bridge_port *port)
 554 {
 555         struct net_port_vlans *pv;
 556         u16 vid;
 557
 558         ASSERT_RTNL();
 559
 560         pv = rtnl_dereference(port->vlan_info);
 561         if (!pv)
 562                 return;
 563
 564         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 565                 vlan_vid_del(port->dev, port->br->vlan_proto, vid);
 566
 567         __vlan_flush(pv);
 568 }
 569
 570 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
 571 {
 572         struct net_port_vlans *pv;
 573         bool found = false;
 574
 575         rcu_read_lock();
 576         pv = rcu_dereference(port->vlan_info);
 577
 578         if (!pv)
 579                 goto out;
 580
 581         if (test_bit(vid, pv->vlan_bitmap))
 582                 found = true;
 583
 584 out:
 585         rcu_read_unlock();
 586         return found;
 587 }